Compressed-air jack.



w.1. BUCH NER & R. F. NORTH. COMPRESSED AIR JACK.

APPLICATION FILED JAN. 19; I918.

1,Q68,8 1 6. Patented June 11, 1918.

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RHYMOND F NOFLTH 6410: neg

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Patented tie it, 11912..

1 3,816, Specification of Letters Patent.

Application filed January 19, me. Serial No. 212,862.

' To all whom it may camera:

Be it known that we, WARREN J. Bnormnn and RAYMOND F. Non'rrr, citizens of the United States, residing at Glendive in the county of Dawson and State of Montana, have invented certain new and useful Improvments in Compressedghr acks, of which the following'is a speclficatlon, refer ence being bad to the accompanying draw- This invention relates to lifting jacks, and particularly to a lifting jack wherein com-..

pressed air is used as the means for lifting the jack.

The general object of the invention is the provision of a lifting jack having a storage chamber and a piston chamber, the storage chamber being provided with means whereby it may be charged with air at a predetermined pressure, and valve connections be provided whereby the air within the storage chamber may be allowed to flow intothe lifting jack chamber to thereby hft the ack proper, and whereby when the lifting operation is completed, air may be caused to flow fromthe lifting jack chamber back to the storage chamber.

A further object of the invention is to rovide means whereby when the article bemg lifted is blocked up, the air may be forcibly withdrawn from the lifting ack chammr and forced into the storage chamber.

Other objects will appear in the course of the following description.

Our ingention is in the accoman rawm w eremr- P rigii 1 is a longitudinal vertical sectional view of a com ressed air lifting Jack constructed in accor ance with our inven tion, the connecting pipes being in elevation Fig. 2 is a top plan view of the construction illustrated in Fig. 1;-

Fig. 3 is an enlarged vertical sectional view, a portion of the head 12 and the cylinder 28, the piston being in elevatlon and Fig. 4 is an enlarged longitudinal sectional view of the check valve in plpe 21.

Referring to these fi 12': 10 designates the storage chamber WlllOh is flanged at its upper and lower ends and closed by the u per and lower heads 11 and 12 respect1ve y. The upper-head is formed with a central perforation 13having a g box or gland This storage chamber 0 is provided with an air inlet nipple 14 and the controlling valve, this nipple being adapted to be connected to any source of compressed air.

Qoacting with the storage chamber 10 i" a ack chamber 15. This is cylindrical in form and closed at its upper and lower ends by means of the heads 16 and 17 respectively, these heads being riveted or bolted to the body of the chamber. Disposed within the chamber 15 is a piston 18 having a plurality of piston rods 19 extending up through suitable opemngs in the upper head 16 and preferably through glands-or stufling boxes in this head, these piston rods carrying upon their upper ends a square or other shaped plate 19. A cushioning spring 20 is disposed around one or more of the piston rods 19 and bears against the upper head 16 so as to resist such-extreme downward movement of the piston 19.

The chamber 15 below the piston is connected by a relatively large pipe 21 to the storage chamber 10. This pipe 21 at its outer end is formed with an elbow 22 and intermediate its length the pipe is provided with a manually controlled cut-0E valve 23 and a check valve 24. which opens in the direction of the jack chamber upon pressure from the storage tank or chamber, but closes when the pressure in the jack T(Shamber exceeds that in the storage cham- Extending from the space below the piston and preferably from the elbow 22 is a relatively small relief pipe 25 having therein a check valve 26 and a hand operated valve 27. The check valve opens toward the storage chamber and the pipe 25 passes through the storage chamber and into a centrally disposed pump cylinder 28, mounted upon the bottom or head 12. The upper and lower ends of this cylinder 28 are closed and 'operatin within this cylinder 28 is a piston 29 having a piston rod 30 extending out through a stufing box 31 in the upper head of the cylinder 11 and out through the opening in the head surrounded by the studing box 13. Attached to the rod 30 is a lever 32 which is mounted upon a link 33 in turn engaged with the head 11.

By means of this lever the piston 29 may be reciprocated. Extending from the cylin der 28 below the piston 29 is a relief pipe 34 having therein a check valve closing to pressure within the storage tank but openmg to pressure from within the cylinder 28.

its

' 1s a pressure gage 35.

. of the valves 23 an position, and preferabl upon the head 11 referably the storage chamber 10 and the jack chamber 15 are mounted. upon a platform 36 having wheels whereby the jack may be readily shifted to any desired osition.

The operation of t is invention is as follows: The storage chamber 10 is filled with air at a certam predetermined pressure. The means for compressing the air within the storage chamber may be of any suitable character and when the storage chamber has been filled with compressed air the valve in the nip 1e 14 is closed. Both 27 are closed and the piston 18 is lowered to its full extent. Now when it is desired to use the jack, the valve 23 is opened and the air in the storage chamber causes the outward movement of the piston 18 and the lifting of the platform 19. When the article being ifted has been lifted a predetermined degree the valve 23 is closed and the air tra ped between the piston 18. and the valve 2 will holdthe article in a raised position. If 1t be desired to block up the article after it has been raised and to remove the jack, then after the article is blocked up, the valve 27 is opened. The weight of the piston alone, however, will not cause the outward assage of air through the pipe 25 and, un er these circumstances, the pump piston 29 is reciprocated, causing the withdrawal of air through the pipe 25 and its discharge through the check valve 34 into the storage tank until the piston 18 has been lowered to its full extent. Where the article which has been raised is designed to be again lowered with the piston, then, of course, the pump piston 29 is reciprocated to withdraw the air through the ipe 25 and discharge it into the stora e c amber 10.

It will be obvious that wit this construction the air always remains under the same degree of compression within the storage chamber 10, except while the jack is in actual use and that the same air is used over and over again, so that once the storage chamber is charged with air under a predetermined degree of compression there is no necessity of recharging t e storage chamber, except as may be caused by' a leakage of air through the stufling boxes. While we have illustrated a construction which we believe to be thoroughly effective for the purposes intended, it is to be understood that many changesmay be made in the details of construction and arrangement of parts, without departing from the spirit of the invention as set forth in the appended claims.

Having described our invention, what we claim is 1. A lifting jack including a compressed air storage chamber, a jack chamber, a iston therein operatively connected to a fting weenie I age chamber to the jack chamber below the piston, one of said connections having a manually operable valve, and a check valve preventing flow of compressed air from the pack chamber, the other connection having a manually operable valve and a check valve permitting flow from the jack chamber to the storage chamber.

2. A lifting jack including a compressed air storage chamber, a jack chamber, a pis ton therein'operatively connected to a lifting member, tubular connections from the storage chamber to the jack chamber below the piston, one of said connections having a manually operable valve, and a check valve preventin flow of compressed air from the ack cham er, the other connection havin a manually operable valve and a check va ve permitting flow from the jack chamber to the storage chamber and means for positively pumping air from thejack chamber to the storage chamber.

3. A lifting jack including a compressed air storage chamber, a jack chamber, a pis ton therein operatively connected to a jack member, tubular connections from the storage chamber to the jack chamberbelow the piston, one of said connections having a manually operable valve, and a check valve preventing flow of compressed air fromthe ack chamber, the other connection having a manually o arable valve and a check valve permitting ow from the jack chamber to the storage chamber, and means for positively pumpin air from the jack" chamber to the storage c amber, said means including a pumping cylinder disposed within the J storage chamber and having an outlet nozzle rovided with an outwardly opening chec valve, a piston operating within the umping chamber and havin a rod extendmg through the storage cham er, and means for operating the iston. I

4. A lifting jac including a compremed "air storage chamber having a valved nipple whereby compressed air may be forced into the storage chamber, a jack chamber having a piston therein operativel connected to a hfting member, a relative y largetubular connection from the stora e chamber to the jack chamber below the piston thereof, said mg the piston 5. A lifting jack including a compressed air storage chamber having means whereby it may be filled with compressed air and havin oppositely disposed heads, a pumping cy inder mounted upon the bottom head and closed at its opposite ends, a piston rod extending through the uppermost head of the pumping cylinder and out through the uppermost-head of the storage chamber, a lever mounted upon the storage chamber and operatively connected to sa1d rod, a jack chamber, a piston therein, rods extending through the upper end of the jack chamber and attached to the piston and carrying a lifting member, a relatively large tubular connection leading from the lower end of the storage chamber to'the jack chamber be low the iston thereof and provided in its length W1th a check valve preventing back flow from the jack chamber, and with a manually operable valve, a relatively smaller tubular connection operatively connected to the jack chamber be ow the piston and extending into the Kumping cylinder and provided in its leng't with a manually operable valve and a check valve openin toward the pumping cylinder, and an out at from the lower end of the pumping cylinder having a 'to the lifting chamber below the check valve opening to pressure within the pumping cylinder.

6. A lifting jack including a wheeled base, a compressed air storage chamber mounted thereon, a jack chamber mounted thereon, a piston in the jack chamber operatively connected to a lifting member, tubular connections from the storage chamber piston therein, one of said connections havmg a manually operable valve, and a check valve preventin flow of compressed air from the jack cham er, the other connection havin a manually operable valve and a check va ve permitting flow from the jack chamber to the storage chamber, and a pump connected to the first named of the said tubular connections and discharging into the storage chamber. I

In testimony whereof we hereunto afix our signatures in the presence of two witnesses. 

